Bromodeoxyuridine (BrdU) is a synthetic nucleoside analogue of thymidine. It is incorporated into the DNA of dividing cells during the S-phase of the cell cycle, substituting for thymidine. This property makes BrdU a valuable tool in
cell proliferation studies.
In histology, BrdU is commonly used to label newly synthesized DNA in proliferating cells. This is achieved by administering BrdU to living organisms or cell cultures, after which the tissue or cells are processed and examined using immunohistochemistry. By using specific
antibodies that recognize BrdU, researchers can visualize and quantify cell proliferation.
BrdU labeling is extensively used in various research fields, including:
The process of BrdU labeling and detection typically involves the following steps:
BrdU Administration: BrdU can be administered via injection, drinking water, or directly added to cell culture media.
Tissue or Cell Collection: After a suitable incorporation period, tissues or cells are collected and fixed.
Denaturation: DNA is denatured to allow antibody access to BrdU. This can be done using acid, heat, or enzymatic treatment.
Immunostaining: Specific antibodies against BrdU are applied, followed by secondary antibodies conjugated to a detectable marker (e.g., fluorescent dyes or enzymes).
Visualization: The labeled cells are visualized using microscopy techniques such as
fluorescence microscopy or
confocal microscopy.
BrdU offers several advantages, including:
High sensitivity and specificity for detecting proliferating cells.
Compatibility with various detection methods, including fluorescence and colorimetric assays.
Ability to quantify cell proliferation rates.
Despite its advantages, BrdU labeling has some limitations and considerations:
BrdU incorporation may be toxic to some cell types.
Denaturation steps can damage tissue morphology.
BrdU labeling provides a snapshot of proliferation at a specific time point, rather than continuous monitoring.
Careful optimization of the BrdU concentration and administration timing is required.
Alternatives to BrdU labeling include:
